Question

A ray AO is incident upon a smooth surface POQ and enters into a denser medium. It is refracted along OS, a normal ON is drawn perpendicular to the surface at O (the point of incidence), and the value of ∠AOP is 60°. Find the probable value of x.

• A. 30°
• B. 15°
• C. 60°
• D. 75°

Answer 1

The correct option is B 15°

Given,
∠AOP = 60°
∠AOP + ∠AON = 90° (As ON is perpendicular to POQ)

∴ ∠AON = 90° - ∠AOP
= 90° - 60°
= 30°

As the light ray enters into a denser medium, the angle of refraction is less than the angle of incidence.

The angle of incidence is ∠AON.

So, ∠x < 30°
Hence, the probable value of ∠x is 15°.